package org.eoti.ai.genetic.gp;

import java.util.Date;
import java.util.Random;

/**
 * The MIT License
 * <p/>
 * Copyright (c) 2009 Malachi de AElfweald (malachid@gmail.com)
 * <p/>
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
 * documentation files (the "Software"), to deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * <p/>
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the
 * Software.
 * <p/>
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
public enum RandomNumber
{
	INSTANCE;
	private Random random = new Random( (new Date()).getTime() );

	private void _randomize()
	{
		// if we are calling quickly, we get duplicates... this is to try to offset it
		int x = random.nextInt();
		int y = random.nextInt();
		while(x == y)
		{
			random.setSeed(random.nextLong());
			random.nextInt();
			random.nextGaussian();
			if(random.nextBoolean())
				random.nextInt();

			random.setSeed(random.nextLong());
		}
	}

	public int nextInt(int maxNumExclusive)
	{
		_randomize();
		return random.nextInt(maxNumExclusive);
	}

	public boolean nextBoolean()
	{
		_randomize();
		return random.nextBoolean();
	}
}
